Apparatus for recovering unused concrete

ABSTRACT

Apparatus and method for recovering unused concrete. A form is provided which is defined by a foundation having a backstop and rails or channel irons secured on the top surface along the sides of the foundation. Unused concrete is poured into the form, leveled to a depth of approximately one-half inch more than the size of the coarse aggregate in the concrete mixture and allowed to achieve final set. Crushing means is then moved forward in the form on the top surface of the foundation so that the hardened unused concrete is broken into relatively small particles which may be used as aggregate in new concrete mixtures.

United States Patent [191 Viner [4 1 Jan. 22, 1974 APPARATUS FOR RECOVERING UNUSED CONCRETE [76] Inventor: Richard L. Viner, lOl 10 Chapel Rd., Potomac, Md. 20854 [22] Filed: Apr. 25, 1972 [21] Appl. No.: 247,464

[52] US. Cl. 241/101.7 [51] Int. Cl. B02c 1/04 [58] Field of Search..... 241/27, 100, 101.4, 249/2,

[56] References Cited UNITED STATES PATENTS 3,389,003 6/1968 Gado 106/97 Primary ExaminerRoy Lake Assistant Examiner-E. F. Desmond [57] ABSTRACT Apparatus and method for recovering unused concrete. A form is provided which is defined by a foundation having a backstop and rails or channel irons secured on the top surface along the sides of the foundation. Unused concrete is poured into the form, leveled to a depth of approximately one-half inch more than the size of the coarse aggregate in the concrete mixture and allowed to achieve final set. Crushing means is then moved forward in the form on the top surface of the foundation so that the hardened unused concrete is broken into relatively small particles which may be used as aggregate in new concrete mixtures.

3 Claims, 5 Drawing Figures APPARATUS FOR RECOVERING UNUSED CONCRETE DESCRIPTION OF THE PRIOR ART This invention relates to a method and apparatus for reclaiming unused concrete, to an aggregate product produced thereby and to concrete mixtures containing the aggregate. The tremendous growth in recent years of metropolitan and suburban areas and the correspondingly increased need for ready-mixed concrete have created a problem of significant proportions for the producers of such concrete. In order to avoid a production lag, contractors will commonly order an excess amount of concrete for use on a particular project. After the requisite amount of concrete has been poured the producer is left with the problem of disposing of the unused concrete which must be removed from the delivery truck before it hardens. A small amount of this unused concrete may be returned to the plant and used in one of many ways, for example, to pave surrounding areas or make concrete products, but the bulk of the unused concrete must be disposed of outside the plant area. Numerous methods have been attempted in the past to reclaim this waste concrete but all have been impractical either because the devices employed take up too much space in the plant area or they are uneconomical to operate. For example, one method includes washing the cement out of the wet concrete and separating the sand and gravel; but this creates environmental problems and its costs are prohibitive. Therefore, the usual procedure is to dump the concrete into quarries or remote areas or to give it away to others who might find a use for it. The main difficulty with these procedures is that coordination is needed between the driver, the plant, and the person receiving the concrete and, in the usual case, valuable time is lost in making this delivery. In addition, in transporting the unused concrete to remote areas, the producer is denied the use of the delivery truck for other operations. Therefore, it has become necessary to develop a practical method for disposing of such unused concrete.

SUMMARY OF THE INVENTION Accordingly, it is the object of the present invention to provide a simple and practical method and apparatus for reclaiming unused concrete.

It is also an object of the present invention to provide a practical method for recovering unused concrete in the form of pre-hardened aggregate which may be reused in concrete mixtures. The accomplishment of these and other objects of the present invention will become apparent from the following disclosure.

According to the invention, the unused concrete is deposited in a form to a depth of about one-half inch or more than the size of the coarse aggregate in the concrete mixture and allowed to achieve final set. After the concrete has dried, crushing means are moved forward in the form so that as it drives forward, the concrete is crushed into small particles which may be used as aggregate in mixing new concrete.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate the best mode presently comtemplated for carrying out the objects of the invention and are not to be construed as restrictions or limitations on its scope. In the drawings:

FIG. 1 is a view in perspective of the apparatus of the present invention before the unused concrete is poured.

FIG. 2 is a view in perspective of the same form after the unused concrete has been poured and hardened.

FIG. 3 is a cross-sectional view of FIG. 2 along lines 3-3.

FIG. 4 is a view in perspective of the hardened unused concrete being crushed into aggregate.

FIG. 5 illustrates another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1 a foundation 1 is formed on grade 2 as illustrated. The foundation is preferably composed of a high density concrete mixture and trowled so as to provide a relatively smooth top surface area 3. If desired, a parting agent, such as oil, may also be applied to the top surface area prior to pouring unused concrete thereon. Rails, preferably channel irons, 4 and 5 are anchored to the top surface area along the sides of the foundation by any convenient means. For example, the channel irons may be embedded in the foundation or may be anchored thereto by a nut and bolt arrangement not shown. The width of the foundation between the channel irons is not critical although a 10 foot width is preferred. A length of about 50 to feet is also preferred. As shown in FIG. 2, the unused concrete is poured into the form which is defined by the channel irons 4 and 5, a backstop or rear barrier 6 and a front barrier 7 (in phantom) which is removed after the concrete has set or hardened. After being poured, the concrete is leveled by appropriate means, such as a metal screed or I-beam section, to a depth of approximately one-half inch more than the side of the coarse aggregate in the concrete mixture and allowed to harden, preferably for 10-24 hours. In the usual case the depth of the formed concrete will be 2-3 inches. After the concrete has finally set, a crushing means, such as a front end loader identified in FIG. 4 by numeral 8, is placed under the forward edge 9 of the formed concrete and driven forward so that it crushes the concrete into small particles 10. These particles, which in the usual case will be a No. 4" size, may be used as aggregate in forming new concrete.

The aggregate formed as above may, of course, be stored just as other gravel or crushed stone for subsequent use.

One of the practical advantages of the invention described above is that its use does not prevent utilization of plant space which is needed for other purposes. For example, concrete may be poured into the forms in the afternoon and usually it will be dried sufficiently in the evening so that it may be utilized as a parking area.

The embodiment illustrated in FIG. 5 will generally be used when space is not at a premium. One end of the channel irons l1 and 12 is flared as shown at 13 and 14 to act as guides for the crushing means, ie. a front end loader.

After the concrete has been crushed into aggregate as above, it may be used in forming new concrete mixtures.

The term concrete as used herein refers to a mixture of cement, sand, and gravel or crushed stone. Typical proportions on a weight basis are 7-l4% cement, 24-30% sand, and 56-69% gravel or crushed stone.

The term cement as used herein refers to Portland cement or the like as is customarily used in the making of concrete. A full description of such materials will be found in the encyclopedia of Chemical Technology, second Edition, Vol. 4 beginning at page 684. For example, Portland cement is typically made by sintering a mixture of raw materials one of which is composed mainly of calcium carbonate and the other of aluminum silicate. The clinkers resulting from sintering this mixture are pulverized with a small amount of gypsum.

Specific examples of such standard concrete mixtures and concrete compositions can be found by referring to the text Industrial Chemistry published by the Reinhold Publishing Corporation beginning on page I60 of the third Edition.

The amount of aggregate material, produced by the abovedescribed method, which is used in forming new concrete mixtures will, of course, vary depending on the desired specification. For example, the new mixture may contain as much as 56-69 percent of the reclaimed aggregate. However, the reclaimed aggregate may also be used along with fresh gravel or stone in formulating new mixtures. For instance, a concrete mixture containing 2-10 percent by weight of reclaimed material and 46-67 percent of new grave] or stone is feasible.

The invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The present embodiments are, therefore, to be considered in all respects as illustrative and l sa.

not restrictive, the scope of the invention being indicated by the claims rather than by the foregoing description, and all changes which come within the meaning and range of the equivalents of the claims are therefore intended to be embraced therein.

means defining a form for a concrete mixture, and

crushing means adapted to move forward on said top surface area substantially along the length of said foundation when said mixture has hardened.

2. An apparatus as defined in claim 1 wherein said top surface area has a substantially smooth texture and said crushing means is a front-end loader.

3. An apparatus as defined in claim 2 wherein said rails are channel irons. 

1. An apparatus for recovering unused concrete which comprises: a foundation having a top surface area; a backstop integral with a rear portion of said foundation; rails extending the length of said foundation and secured to the top surface area along the side edges thereof; barrier means removably positioned on said top surface area substantially near a front edge of said foundation; said top surface area, backstop, rails and barrier means defining a form for a concrete mixture, and crushing means adapted to move forward on said top surface area substantially along the length of said foundation when said mixture has hardened.
 2. An apparatus as defined in claim 1 wherein said top surface area has a substantially smooth texture and said crushing means is a front-end loader.
 3. An apparatus as defined in claim 2 wherein said rails are channel irons. 